Two-photon imaging can provide dynamic information about the behavior of pathogens and immune cells in[unreadable] tissues during infection. Such information can provide unique insight into the course of events during[unreadable] infection and the impact of therapeutic treatments. However, this technique is outside the reach of many[unreadable] investigators due to the cost of purchasing and maintaining equipment, and the challenges in preparing[unreadable] samples and analyzing data. In this proposal we plan to make this powerful tool available to the[unreadable] investigators of the PO1 by: (1) working with individual labs on pilot studies to determine the optimal[unreadable] experimental set-ups to meet individual imaging goal, (2) expanding existing imaging equipment to provide[unreadable] more access, and (3) assisting individual labs to make use of quantitation software and perform[unreadable] mathematical analysis of visual data.